Method of edge finishing shoe parts



Oct. 21, 1941. A. v. PIQAEDEL 2,259,583

METHOD OF EDGE FINISHING SHOE PARTS Filed July 13, 1940 2 Sheets-Sheet l I o o I k 0 3 J S Q y 0- 69 o l W 25 To? 6 20W I: /a Y I 2 @D Q" I 0 O W 24 I 1, 9

0 g B 22 0 o 44 0 Fig.1

Wl/E/VTUF Oct. 21, 1941. A. v. PRAEDEL 2,259,583

METHOD OF EDGE FINISHING SHOE PARTS Filed July 15, 1940 2 Sheets-Sheet 2 Fig.5 Fig.4

Patented Oct. 21, 1941 azsasse;

oFFIc-El 7 METHOD or nude Fmsnma snoarARr-s I Jersey Application July 13, 1940, Serial No. 345,330

7 Claims.

This invention relates to methods of finishing the edges of shoe parts and will be illustratively described as carried out in the finishing of the rear edges of toe tips, especially where it is desired to make a pinking out along those edges.

For certain classes of shoes the exposed edges of the upper parts are sometimes raw edges which are made more attractive by making a zigzag, pinking out along the edge. As a result of the fibrous nature of leather, such pinking cuts are apt to be somewhat fuzzy, unless the pinking knife is exceedingly sharp. Accordingly, the present invention provides a method which comprises compacting a portion of a piece of leather by searing or hammering, or both these operations, and thereafter trimming the piece by a cut made through the compacted portion. When this method is practiced a clean out can be made irrespective of the kind of leather which is employed.

In the drawings Fig. 1 is a plan view of a portion of a machine which may be conveniently used for carrying out the method;

Fig. 2 is a detail view showing the skiving mechanism of this machine on a larger scale;

Fig. 3 shows the searing tool;

Fig. 4 shows, in vertical section, a pinking tool and an associated perforating tool;

Figs. 5 and 6 are a side elevation and a plan view of the pinking and perforating die; and

Figs. 7 and 8 illustrate in radial section and, in angular view, a portion of a piece of work which has been treated in accordance with my novel method.

The illustrated machine is in general like that of the machine disclosed in United States Letters Patent No, 1,989,682, granted February 5, 1935, on an application filed in the name of John B. Cofiey, except that it is provided with a pinking tool. The machine is provided with a rotary turret I0 having a series of carriers which are provided with clamping jaws I2 by means of which toe tips with their rear margins I4 projecting from the jaws are carried from a loading station I 6 to a searing station I8 and thence to a perforating and pinking station 20, after which they are released by the clamps and allowed to drop into a suitable receptacle 22 at the delivery station. At the searing station the edge of the work is first treated by skiving knives 24 and is then subjected to the action of a searing tool 26 which shrinks the leather and causes the edge of it to curl, after which the edge is further compacted by a hammer 28, The skiving knives comprise an oscillatory member 30 which coacts with a fixed supporting member 32, and these are so arranged that the angle of incidence of the cut may be varied. The searing tool 26 comprises a U- shaped member having a crossbar 34 which rests upon the work and which is heated white hot by any suitable means, such as the passage of an electric current therethrough. Associated with this searing tool is a plow 35 to aid in turning up the curled edge. After having been further compacted by the driven hammer 28, the tips are successively presented to the pinking and perforating station 20, where there is provided a platen 35 and a die 38 having an arcuate pinking blade 40 attached to one face thereof. If it is desired also to perforate the work, then the die will be provided with a series of tubes 42, 44 and with a stripper plate 46 which holds the work firmly against the platen 36. The organization of the machine is such that the work is carried forward a sufiicient distance at each reciprocation of the platen 36 so that the pattern of the punching and pinking mechanism may be repeated.

It is important to note from an inspection of Figs. 4, 7 and 8 that the cut made by the pinking blade 40 lies inside of the curled portion 50 caused by the conjoint action of the searing tool 26 and the associated plow 35. At the side toward the body of the tip, the zigzag cut does not extend beyond the inner border 52 of the seared, shrunken, and compacted margin 54 which is caused by the treatment provided at the searing station l8. Consequently, the pinking cut will pass from the grain surface 56 of the leather toward the flesh surface 38 thereof and will intersect only the fibres which have been thoroughly shrunken and compacted by the action described above. As a result, loose fibres and a fuzzy appearance are avoided.

Having thus described my invention, which I claim as new and desire to secure by Letters Patent of the United States is:

1. That improvement in methods of treating shoe parts which consists in searing a marginal portion of a part and in trimming the part by a cut made through the seared portion.

2. That improvement in methods of treating leather shoe parts which consists in shrinking a portion of the margin of a shoe part by heat applied to the flesh surface thereof and in then trimming the part by cutting through the shrunken portion.

3. That improvement in methodsof treating leather shoe parts which consists in shrinking part, searing the flesh surface of the skived pertion, and making a pinking cut extending through the seared portion.

6. That method of treating shoe parts which consists in searing the margins of said parts, hammering th-e seared portions to compact them still more, and pinking the edge by a cut extending through the seared and compacted portion.

7. That method of treating shoe tips which consists in skiving the rear edges of said tips, searing th'e flesh surface of the tips at the skived portion, hammering the tips adjacent to the seared portion thereby still further to compact them, and making a plnking cut through the scared and compacted margin.

ARNOLD V. PRAEDEL. 

